A new route for the hydrothermal synthesis of Eu doped tin oxide nanoparticles D. Tarabasanu-Mihaila1*, L. Diamandescu1, M. Feder1, S. Constantinescu1, V.S. Teodorescu1, S. Georgescu2, A. Banuta1 1 National Institute of Materials Physics,

1
A new route for the hydrothermal
synthesis of Eu doped tin oxide
nanoparticles D. Tarabasanu-Mihaila1, L.
Diamandescu1, M. Feder1, S. Constantinescu1, V.S.
Teodorescu1, S. Georgescu2, A. Banuta11 National
Institute of Materials Physics, P.O. BOX MG-7,
Bucharest, Romania 2 National Institute of
Laser Plasma Radiation Physics, P.O. BOX
MG-36, Bucharest, Romania

• STATE OF THE ART AND OBJECTIVE

EXPERIMENTAL

• SnO2 is an attractive semiconductor, host lattice
  for optical active rare earths ions owing to its
  chemical stability and electronic and optical
  properties (wide band gap of 3.6 eV, high
  transparency in the visible light region).
• SnO2 based luminescent materials (phosphors) have
  been synthetized by various methods sol-gel,
  radio-frecvency sputtering, microwave
  assisted-solvothermal route, coprecipitation
  etc. 1-3.
• Eu3 ions exhibit an intense red light emission
  arising from 5D0?7Fj transition Eu3 doped SnO2
  emits an unique reddish-orange color.
• The solubility limit of Eu3 in SnO2 is low
  (0,5-8 at) because of the difference in the
  ionic radius and chemical valence state of Eu3
  and Sn4. At higher doping concentration, the
  excess of Eu3 may seggregate on the
  nanoparticle surface as separated phases.
•  
• This study reports on the new route for the
  hydrothermal synthesis of EuSnO2 nanocrystalline
  oxides, extending the solubility range to 20 at
  Eu, together with the structural and
  morphological characterization of the obtained
  nanostructures.

Hydrothermal synthesis route
LUMINESCENCE
TEM / EDX
TEM images and EDX spectrum of the sample with 6
at Eu the atomic ratio Eu/Sn given by EDX
5.9/94.1 ? 6.8/93.2.
Luminescence spectra for the hydrothermal sample
3 at Eu SnO2, as resulted (a) and after
calcination at 650 C (b).
MÖSSBAUER SPECTROSCOPY ON 151Eu
CONCLUSION


Eu doped SnO2
nanoscaled powders were obtained in an extended
solubility range (up to 20 at. Eu)
directly, by a new hydrothermal route at moderate
temperature (250 ?C) The
nanocrystalline EuSnO2 powders have the
cassiterite structure (rutile type) The
mean particle size is 3-5 nm for as resulted
hydrothermal samples and 5-10 nm for the
calcinated powders Eu3 ions can
substitute for Sn4 or can enter interstitially
in the SnO2 nanostructure. At Eu/Sn
concentration ratio 1/1 (50 at Eu), well
crystallized cubic Eu2Sn2O7 (compound of
interest in high temperature catalytic
application) has been obtained.

Mössbauer spectrum on 151Eu for the hydrothermal
sample at 6 at Eu SnO2 (left) in comparison
with Eu2O3 Mössbauer spectrum (right) showing
the presence of many inequivalent Eu sites in
the SnO2 structure.

• References
• E. A. Morais, L. V. A. Scalvi, A. Tabata,
  Photoluminescence of Eu3 Ion in SnO2 Obtained
  by SolGel, J. Mater. Sci., 43, 1 (2008)
  345349.
• 2. T. H. Moon, S. T. Hwang, D. R. Jung,
  Hydroxyl-Quenching Effects on the
  Photoluminescence Properties of SnO2Eu3
  Nanoparticles, J. Phys. Chem. C,111,11 (2007)
  41644167.
• 3. D.H. Park, Y.H. Cho, Y.R. Do, B.T. Ahn,
  Characterization of Eu- Doped SnO2 Thin Films
  Deposited by Radio-Frequency Sputtering for a
  Transparent Conductive Phosphor Layer,
  J.Electrochem. Soc.,153, 4 (2006) H63H67 .

)
Acknowledgements. This work was prepared with the
support of the Romanian Ministry of Education and
Research, under the Core Program PN09-450102.
Corresponding author doinat_at_infim.ro
A 10-a editie a Seminarului National de
nanostiinta si nanotehnologie
18 mai 2011 Biblioteca Academiei Romane